I know the lithium batteries are supposed to be a pain to recycle but how are the conventional ones broken down to recover all the materials?
I have a bucket I throw dead batteries into and picking it up made me realize just how heavy it is. That is a lot of metal. And metal is money.
They are shredded to small pieces. A magnet separates all ferromagnetic parts, like steel casings. There can also be other separation methods such as flotation. Various non-ferromagnetic materials such as zinc and manganese can be dissolved in sulfuric acid. In order to speed things up, leaching is done at an elevated temperature. By tweaking the leaching parameters, it’s possible to dissolve Zn and Mn selectively.
In the next stage, Mn and Zn are selectively precipitated as hydroxides using something like sodium hydroxide for example. There are other options too. You could also melt the batteries and separate the metals that way. If you use pyrometallurgy instead of hydrometallurgy, you’ll be using a lot more energy, and there can be CO2 emissions.